xref: /freebsd/bin/pax/pax.1 (revision 3642298923e528d795e3a30ec165d2b469e28b40)
1.\"-
2.\" Copyright (c) 1992 Keith Muller.
3.\" Copyright (c) 1992, 1993
4.\"	The Regents of the University of California.  All rights reserved.
5.\"
6.\" This code is derived from software contributed to Berkeley by
7.\" Keith Muller of the University of California, San Diego.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\"    notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\"    notice, this list of conditions and the following disclaimer in the
16.\"    documentation and/or other materials provided with the distribution.
17.\" 4. Neither the name of the University nor the names of its contributors
18.\"    may be used to endorse or promote products derived from this software
19.\"    without specific prior written permission.
20.\"
21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31.\" SUCH DAMAGE.
32.\"
33.\"	@(#)pax.1	8.4 (Berkeley) 4/18/94
34.\" $FreeBSD$
35.\"
36.Dd July 3, 2004
37.Dt PAX 1
38.Os
39.Sh NAME
40.Nm pax
41.Nd read and write file archives and copy directory hierarchies
42.Sh SYNOPSIS
43.Nm
44.Op Fl cdnvz
45.Bk -words
46.Op Fl f Ar archive
47.Ek
48.Bk -words
49.Op Fl s Ar replstr
50.Ar ...\&
51.Ek
52.Bk -words
53.Op Fl U Ar user
54.Ar ...\&
55.Ek
56.Bk -words
57.Op Fl G Ar group
58.Ar ...\&
59.Ek
60.Bk -words
61.Oo
62.Fl T
63.Op Ar from_date
64.Op Ar ,to_date
65.Oc
66.Ar ...\&
67.Ek
68.Op Ar pattern ...\&
69.Nm
70.Fl r
71.Op Fl cdiknuvzDYZ
72.Bk -words
73.Op Fl f Ar archive
74.Ek
75.Bk -words
76.Op Fl o Ar options
77.Ar ...\&
78.Ek
79.Bk -words
80.Op Fl p Ar string
81.Ar ...\&
82.Ek
83.Bk -words
84.Op Fl s Ar replstr
85.Ar ...\&
86.Ek
87.Op Fl E Ar limit
88.Bk -words
89.Op Fl U Ar user
90.Ar ...\&
91.Ek
92.Bk -words
93.Op Fl G Ar group
94.Ar ...\&
95.Ek
96.Bk -words
97.Oo
98.Fl T
99.Op Ar from_date
100.Op Ar ,to_date
101.Oc
102.Ar ...\&
103.Ek
104.Op Ar pattern ...\&
105.Nm
106.Fl w
107.Op Fl dituvzHLPX
108.Bk -words
109.Op Fl b Ar blocksize
110.Ek
111.Oo
112.Op Fl a
113.Op Fl f Ar archive
114.Oc
115.Bk -words
116.Op Fl x Ar format
117.Ek
118.Bk -words
119.Op Fl s Ar replstr
120.Ar ...\&
121.Ek
122.Bk -words
123.Op Fl o Ar options
124.Ar ...\&
125.Ek
126.Bk -words
127.Op Fl U Ar user
128.Ar ...\&
129.Ek
130.Bk -words
131.Op Fl G Ar group
132.Ar ...\&
133.Ek
134.Bk -words
135.Op Fl B Ar bytes
136.Ek
137.Bk -words
138.Oo
139.Fl T
140.Op Ar from_date
141.Op Ar ,to_date
142.Op Ar /[c][m]
143.Oc
144.Ar ...\&
145.Ek
146.Op Ar
147.Nm
148.Fl r
149.Fl w
150.Op Fl diklntuvDHLPXYZ
151.Bk -words
152.Op Fl p Ar string
153.Ar ...\&
154.Ek
155.Bk -words
156.Op Fl s Ar replstr
157.Ar ...\&
158.Ek
159.Bk -words
160.Op Fl U Ar user
161.Ar ...\&
162.Ek
163.Bk -words
164.Op Fl G Ar group
165.Ar ...\&
166.Ek
167.Bk -words
168.Oo
169.Fl T
170.Op Ar from_date
171.Op Ar ,to_date
172.Op Ar /[c][m]
173.Oc
174.Ar ...\&
175.Ek
176.Op Ar
177.Ar directory
178.Sh DESCRIPTION
179The
180.Nm
181utility will read, write, and list the members of an archive file,
182and will copy directory hierarchies.
183These operations are independent of the specific archive format,
184and support a wide variety of different archive formats.
185A list of supported archive formats can be found under the description of the
186.Fl x
187option.
188.Pp
189The presence of the
190.Fl r
191and the
192.Fl w
193options specifies which of the following functional modes
194.Nm
195will operate under:
196.Em list , read , write ,
197and
198.Em copy .
199.Bl -tag -width 6n
200.It <none>
201.Em List .
202Write to
203.Dv standard output
204a table of contents of the members of the archive file read from
205.Dv standard input ,
206whose pathnames match the specified
207.Ar patterns .
208The table of contents contains one filename per line
209and is written using single line buffering.
210.It Fl r
211.Em Read .
212Extract the members of the archive file read from the
213.Dv standard input ,
214with pathnames matching the specified
215.Ar patterns .
216The archive format and blocking is automatically determined on input.
217When an extracted file is a directory, the entire file hierarchy
218rooted at that directory is extracted.
219All extracted files are created relative to the current file hierarchy.
220The setting of ownership, access and modification times, and file mode of
221the extracted files are discussed in more detail under the
222.Fl p
223option.
224.It Fl w
225.Em Write .
226Write an archive containing the
227.Ar file
228operands to
229.Dv standard output
230using the specified archive format.
231When no
232.Ar file
233operands are specified, a list of files to copy with one per line is read from
234.Dv standard input .
235When a
236.Ar file
237operand is also a directory, the entire file hierarchy rooted
238at that directory will be included.
239.It Fl r Fl w
240.Em Copy .
241Copy the
242.Ar file
243operands to the destination
244.Ar directory .
245When no
246.Ar file
247operands are specified, a list of files to copy with one per line is read from
248the
249.Dv standard input .
250When a
251.Ar file
252operand is also a directory the entire file
253hierarchy rooted at that directory will be included.
254The effect of the
255.Em copy
256is as if the copied files were written to an archive file and then
257subsequently extracted, except that there may be hard links between
258the original and the copied files (see the
259.Fl l
260option below).
261.Pp
262.Em Warning :
263The destination
264.Ar directory
265must not be one of the
266.Ar file
267operands or a member of a file hierarchy rooted at one of the
268.Ar file
269operands.
270The result of a
271.Em copy
272under these conditions is unpredictable.
273.El
274.Pp
275While processing a damaged archive during a
276.Em read
277or
278.Em list
279operation,
280.Nm
281will attempt to recover from media defects and will search through the archive
282to locate and process the largest number of archive members possible (see the
283.Fl E
284option for more details on error handling).
285.Sh OPERANDS
286The
287.Ar directory
288operand specifies a destination directory pathname.
289If the
290.Ar directory
291operand does not exist, or it is not writable by the user,
292or it is not of type directory,
293.Nm
294will exit with a non-zero exit status.
295.Pp
296The
297.Ar pattern
298operand is used to select one or more pathnames of archive members.
299Archive members are selected using the pattern matching notation described
300by
301.Xr fnmatch 3 .
302When the
303.Ar pattern
304operand is not supplied, all members of the archive will be selected.
305When a
306.Ar pattern
307matches a directory, the entire file hierarchy rooted at that directory will
308be selected.
309When a
310.Ar pattern
311operand does not select at least one archive member,
312.Nm
313will write these
314.Ar pattern
315operands in a diagnostic message to
316.Dv standard error
317and then exit with a non-zero exit status.
318.Pp
319The
320.Ar file
321operand specifies the pathname of a file to be copied or archived.
322When a
323.Ar file
324operand does not select at least one archive member,
325.Nm
326will write these
327.Ar file
328operand pathnames in a diagnostic message to
329.Dv standard error
330and then exit with a non-zero exit status.
331.Sh OPTIONS
332The following options are supported:
333.Bl -tag -width 4n
334.It Fl r
335Read an archive file from
336.Dv standard input
337and extract the specified
338.Ar files .
339If any intermediate directories are needed in order to extract an archive
340member, these directories will be created as if
341.Xr mkdir 2
342was called with the bitwise inclusive
343.Dv OR
344of
345.Dv S_IRWXU , S_IRWXG ,
346and
347.Dv S_IRWXO
348as the mode argument.
349When the selected archive format supports the specification of linked
350files and these files cannot be linked while the archive is being extracted,
351.Nm
352will write a diagnostic message to
353.Dv standard error
354and exit with a non-zero exit status at the completion of operation.
355.It Fl w
356Write files to the
357.Dv standard output
358in the specified archive format.
359When no
360.Ar file
361operands are specified,
362.Dv standard input
363is read for a list of pathnames with one per line without any leading or
364trailing
365.Aq blanks .
366.It Fl a
367Append
368.Ar files
369to the end of an archive that was previously written.
370If an archive format is not specified with a
371.Fl x
372option, the format currently being used in the archive will be selected.
373Any attempt to append to an archive in a format different from the
374format already used in the archive will cause
375.Nm
376to exit immediately
377with a non-zero exit status.
378The blocking size used in the archive volume where writing starts
379will continue to be used for the remainder of that archive volume.
380.Pp
381.Em Warning :
382Many storage devices are not able to support the operations necessary
383to perform an append operation.
384Any attempt to append to an archive stored on such a device may damage the
385archive or have other unpredictable results.
386Tape drives in particular are more likely to not support an append operation.
387An archive stored in a regular file system file or on a disk device will
388usually support an append operation.
389.It Fl b Ar blocksize
390When
391.Em writing
392an archive,
393block the output at a positive decimal integer number of
394bytes per write to the archive file.
395The
396.Ar blocksize
397must be a multiple of 512 bytes with a maximum of 64512 bytes.
398Archives larger than 32256 bytes violate the
399.Tn POSIX
400standard and will not be portable to all systems.
401A
402.Ar blocksize
403can end with
404.Li k
405or
406.Li b
407to specify multiplication by 1024 (1K) or 512, respectively.
408A pair of
409.Ar blocksizes
410can be separated by
411.Li x
412to indicate a product.
413A specific archive device may impose additional restrictions on the size
414of blocking it will support.
415When blocking is not specified, the default
416.Ar blocksize
417is dependent on the specific archive format being used (see the
418.Fl x
419option).
420.It Fl c
421Match all file or archive members
422.Em except
423those specified by the
424.Ar pattern
425and
426.Ar file
427operands.
428.It Fl d
429Cause files of type directory being copied or archived, or archive members of
430type directory being extracted, to match only the directory file or archive
431member and not the file hierarchy rooted at the directory.
432.It Fl f Ar archive
433Specify
434.Ar archive
435as the pathname of the input or output archive, overriding the default
436.Dv standard input
437(for
438.Em list
439and
440.Em read )
441or
442.Dv standard output
443(for
444.Em write ) .
445A single archive may span multiple files and different archive devices.
446When required,
447.Nm
448will prompt for the pathname of the file or device of the next volume in the
449archive.
450.It Fl i
451Interactively rename files or archive members.
452For each archive member matching a
453.Ar pattern
454operand or each file matching a
455.Ar file
456operand,
457.Nm
458will prompt to
459.Pa /dev/tty
460giving the name of the file, its file mode and its modification time.
461The
462.Nm
463utility will then read a line from
464.Pa /dev/tty .
465If this line is blank, the file or archive member is skipped.
466If this line consists of a single period, the
467file or archive member is processed with no modification to its name.
468Otherwise, its name is replaced with the contents of the line.
469The
470.Nm
471utility will immediately exit with a non-zero exit status if
472.Dv <EOF>
473is encountered when reading a response or if
474.Pa /dev/tty
475cannot be opened for reading and writing.
476.It Fl k
477Do not overwrite existing files.
478.It Fl l
479Link files.
480(The letter ell).
481In the
482.Em copy
483mode
484.Pq Fl r w ,
485hard links are made between the source and destination file hierarchies
486whenever possible.
487.It Fl n
488Select the first archive member that matches each
489.Ar pattern
490operand.
491No more than one archive member is matched for each
492.Ar pattern .
493When members of type directory are matched, the file hierarchy rooted at that
494directory is also matched (unless
495.Fl d
496is also specified).
497.It Fl o Ar options
498Information to modify the algorithm for extracting or writing archive files
499which is specific to the archive format specified by
500.Fl x .
501In general,
502.Ar options
503take the form:
504.Cm name=value
505.It Fl p Ar string
506Specify one or more file characteristic options (privileges).
507The
508.Ar string
509option-argument is a string specifying file characteristics to be retained or
510discarded on extraction.
511The string consists of the specification characters
512.Cm a , e , m , o ,
513and
514.Cm p .
515Multiple characteristics can be concatenated within the same string
516and multiple
517.Fl p
518options can be specified.
519The meaning of the specification characters are as follows:
520.Bl -tag -width 2n
521.It Cm a
522Do not preserve file access times.
523By default, file access times are preserved whenever possible.
524.It Cm e
525.Sq Preserve everything ,
526the user ID, group ID, file mode bits,
527file access time, and file modification time.
528This is intended to be used by
529.Em root ,
530someone with all the appropriate privileges, in order to preserve all
531aspects of the files as they are recorded in the archive.
532The
533.Cm e
534flag is the sum of the
535.Cm o
536and
537.Cm p
538flags.
539.It Cm m
540Do not preserve file modification times.
541By default, file modification times are preserved whenever possible.
542.It Cm o
543Preserve the user ID and group ID.
544.It Cm p
545.Sq Preserve
546the file mode bits.
547This intended to be used by a
548.Em user
549with regular privileges who wants to preserve all aspects of the file other
550than the ownership.
551The file times are preserved by default, but two other flags are offered to
552disable this and use the time of extraction instead.
553.El
554.Pp
555In the preceding list,
556.Sq preserve
557indicates that an attribute stored in the archive is given to the
558extracted file, subject to the permissions of the invoking
559process.
560Otherwise the attribute of the extracted file is determined as
561part of the normal file creation action.
562If neither the
563.Cm e
564nor the
565.Cm o
566specification character is specified, or the user ID and group ID are not
567preserved for any reason,
568.Nm
569will not set the
570.Dv S_ISUID
571.Em ( setuid )
572and
573.Dv S_ISGID
574.Em ( setgid )
575bits of the file mode.
576If the preservation of any of these items fails for any reason,
577.Nm
578will write a diagnostic message to
579.Dv standard error .
580Failure to preserve these items will affect the final exit status,
581but will not cause the extracted file to be deleted.
582If the file characteristic letters in any of the string option-arguments are
583duplicated or conflict with each other, the one(s) given last will take
584precedence.
585For example, if
586.Dl Fl p Ar eme
587is specified, file modification times are still preserved.
588.It Fl s Ar replstr
589Modify the file or archive member names specified by the
590.Ar pattern
591or
592.Ar file
593operands according to the substitution expression
594.Ar replstr ,
595using the syntax of the
596.Xr ed 1
597utility regular expressions.
598The format of these regular expressions are:
599.Dl /old/new/[gp]
600As in
601.Xr ed 1 ,
602.Cm old
603is a basic regular expression and
604.Cm new
605can contain an ampersand (&), \\n (where n is a digit) back-references,
606or subexpression matching.
607The
608.Cm old
609string may also contain
610.Dv <newline>
611characters.
612Any non-null character can be used as a delimiter (/ is shown here).
613Multiple
614.Fl s
615expressions can be specified.
616The expressions are applied in the order they are specified on the
617command line, terminating with the first successful substitution.
618The optional trailing
619.Cm g
620continues to apply the substitution expression to the pathname substring
621which starts with the first character following the end of the last successful
622substitution.
623The first unsuccessful substitution stops the operation of the
624.Cm g
625option.
626The optional trailing
627.Cm p
628will cause the final result of a successful substitution to be written to
629.Dv standard error
630in the following format:
631.Dl <original pathname> >> <new pathname>
632File or archive member names that substitute to the empty string
633are not selected and will be skipped.
634.It Fl t
635Reset the access times of any file or directory read or accessed by
636.Nm
637to be the same as they were before being read or accessed by
638.Nm .
639.It Fl u
640Ignore files that are older (having a less recent file modification time)
641than a pre-existing file or archive member with the same name.
642During
643.Em read ,
644an archive member with the same name as a file in the file system will be
645extracted if the archive member is newer than the file.
646During
647.Em write ,
648a file system member with the same name as an archive member will be
649written to the archive if it is newer than the archive member.
650During
651.Em copy ,
652the file in the destination hierarchy is replaced by the file in the source
653hierarchy or by a link to the file in the source hierarchy if the file in
654the source hierarchy is newer.
655.It Fl v
656During a
657.Em list
658operation, produce a verbose table of contents using the format of the
659.Xr ls 1
660utility with the
661.Fl l
662option.
663For pathnames representing a hard link to a previous member of the archive,
664the output has the format:
665.Dl <ls -l listing> == <link name>
666For pathnames representing a symbolic link, the output has the format:
667.Dl <ls -l listing> => <link name>
668Where <ls -l listing> is the output format specified by the
669.Xr ls 1
670utility when used with the
671.Fl l
672option.
673Otherwise for all the other operational modes
674.Em ( read , write ,
675and
676.Em copy ) ,
677pathnames are written and flushed to
678.Dv standard error
679without a trailing
680.Dv <newline>
681as soon as processing begins on that file or
682archive member.
683The trailing
684.Dv <newline> ,
685is not buffered, and is written only after the file has been read or written.
686.It Fl x Ar format
687Specify the output archive format, with the default format being
688.Ar ustar .
689The
690.Nm
691utility currently supports the following formats:
692.Bl -tag -width "sv4cpio"
693.It Ar cpio
694The extended cpio interchange format specified in the
695.St -p1003.2
696standard.
697The default blocksize for this format is 5120 bytes.
698Inode and device information about a file (used for detecting file hard links
699by this format) which may be truncated by this format is detected by
700.Nm
701and is repaired.
702.It Ar bcpio
703The old binary cpio format.
704The default blocksize for this format is 5120 bytes.
705This format is not very portable and should not be used when other formats
706are available.
707Inode and device information about a file (used for detecting file hard links
708by this format) which may be truncated by this format is detected by
709.Nm
710and is repaired.
711.It Ar sv4cpio
712The System V release 4 cpio.
713The default blocksize for this format is 5120 bytes.
714Inode and device information about a file (used for detecting file hard links
715by this format) which may be truncated by this format is detected by
716.Nm
717and is repaired.
718.It Ar sv4crc
719The System V release 4 cpio with file crc checksums.
720The default blocksize for this format is 5120 bytes.
721Inode and device information about a file (used for detecting file hard links
722by this format) which may be truncated by this format is detected by
723.Nm
724and is repaired.
725.It Ar tar
726The old
727.Bx
728tar format as found in
729.Bx 4.3 .
730The default blocksize for this format is 10240 bytes.
731Pathnames stored by this format must be 100 characters or less in length.
732Only
733.Em regular
734files,
735.Em hard links , soft links ,
736and
737.Em directories
738will be archived (other file system types are not supported).
739For backwards compatibility with even older tar formats, a
740.Fl o
741option can be used when writing an archive to omit the storage of directories.
742This option takes the form:
743.Dl Fl o Cm write_opt=nodir
744.It Ar ustar
745The extended tar interchange format specified in the
746.St -p1003.2
747standard.
748The default blocksize for this format is 10240 bytes.
749Pathnames stored by this format must be 250 characters or less in length.
750.El
751.Pp
752The
753.Nm
754utility will detect and report any file that it is unable to store or extract
755as the result of any specific archive format restrictions.
756The individual archive formats may impose additional restrictions on use.
757Typical archive format restrictions include (but are not limited to):
758file pathname length, file size, link pathname length and the type of the file.
759.It Fl z
760Use
761.Xr gzip 1
762to compress (decompress) the archive while writing (reading).
763Incompatible with
764.Fl a .
765.It Fl B Ar bytes
766Limit the number of bytes written to a single archive volume to
767.Ar bytes .
768The
769.Ar bytes
770limit can end with
771.Li m ,
772.Li k ,
773or
774.Li b
775to specify multiplication by 1048576 (1M), 1024 (1K) or 512, respectively.
776A pair of
777.Ar bytes
778limits can be separated by
779.Li x
780to indicate a product.
781.Pp
782.Em Warning :
783Only use this option when writing an archive to a device which supports
784an end of file read condition based on last (or largest) write offset
785(such as a regular file or a tape drive).
786The use of this option with a floppy or hard disk is not recommended.
787.It Fl D
788This option is the same as the
789.Fl u
790option, except that the file inode change time is checked instead of the
791file modification time.
792The file inode change time can be used to select files whose inode information
793(e.g.\& uid, gid, etc.) is newer than a copy of the file in the destination
794.Ar directory .
795.It Fl E Ar limit
796Limit the number of consecutive read faults while trying to read a flawed
797archives to
798.Ar limit .
799With a positive
800.Ar limit ,
801.Nm
802will attempt to recover from an archive read error and will
803continue processing starting with the next file stored in the archive.
804A
805.Ar limit
806of 0 will cause
807.Nm
808to stop operation after the first read error is detected on an archive volume.
809A
810.Ar limit
811of
812.Li NONE
813will cause
814.Nm
815to attempt to recover from read errors forever.
816The default
817.Ar limit
818is a small positive number of retries.
819.Pp
820.Em Warning :
821Using this option with
822.Li NONE
823should be used with extreme caution as
824.Nm
825may get stuck in an infinite loop on a very badly flawed archive.
826.It Fl G Ar group
827Select a file based on its
828.Ar group
829name, or when starting with a
830.Cm # ,
831a numeric gid.
832A '\\' can be used to escape the
833.Cm # .
834Multiple
835.Fl G
836options may be supplied and checking stops with the first match.
837.It Fl H
838Follow only command line symbolic links while performing a physical file
839system traversal.
840.It Fl L
841Follow all symbolic links to perform a logical file system traversal.
842.It Fl P
843Do not follow symbolic links, perform a physical file system traversal.
844This is the default mode.
845.It Fl T Ar [from_date][,to_date][/[c][m]]
846Allow files to be selected based on a file modification or inode change
847time falling within a specified time range of
848.Ar from_date
849to
850.Ar to_date
851(the dates are inclusive).
852If only a
853.Ar from_date
854is supplied, all files with a modification or inode change time
855equal to or younger are selected.
856If only a
857.Ar to_date
858is supplied, all files with a modification or inode change time
859equal to or older will be selected.
860When the
861.Ar from_date
862is equal to the
863.Ar to_date ,
864only files with a modification or inode change time of exactly that
865time will be selected.
866.Pp
867When
868.Nm
869is in the
870.Em write
871or
872.Em copy
873mode, the optional trailing field
874.Ar [c][m]
875can be used to determine which file time (inode change, file modification or
876both) are used in the comparison.
877If neither is specified, the default is to use file modification time only.
878The
879.Ar m
880specifies the comparison of file modification time (the time when
881the file was last written).
882The
883.Ar c
884specifies the comparison of inode change time (the time when the file
885inode was last changed; e.g.\& a change of owner, group, mode, etc).
886When
887.Ar c
888and
889.Ar m
890are both specified, then the modification and inode change times are
891both compared.
892The inode change time comparison is useful in selecting files whose
893attributes were recently changed or selecting files which were recently
894created and had their modification time reset to an older time (as what
895happens when a file is extracted from an archive and the modification time
896is preserved).
897Time comparisons using both file times is useful when
898.Nm
899is used to create a time based incremental archive (only files that were
900changed during a specified time range will be archived).
901.Pp
902A time range is made up of six different fields and each field must contain two
903digits.
904The format is:
905.Dl [yy[mm[dd[hh]]]]mm[.ss]
906Where
907.Cm yy
908is the last two digits of the year,
909the first
910.Cm mm
911is the month (from 01 to 12),
912.Cm dd
913is the day of the month (from 01 to 31),
914.Cm hh
915is the hour of the day (from 00 to 23),
916the second
917.Cm mm
918is the minute (from 00 to 59),
919and
920.Cm ss
921is the seconds (from 00 to 59).
922The minute field
923.Cm mm
924is required, while the other fields are optional and must be added in the
925following order:
926.Dl Cm hh , dd , mm , yy .
927The
928.Cm ss
929field may be added independently of the other fields.
930Time ranges are relative to the current time, so
931.Dl Fl T Ar 1234/cm
932would select all files with a modification or inode change time
933of 12:34 PM today or later.
934Multiple
935.Fl T
936time range can be supplied and checking stops with the first match.
937.It Fl U Ar user
938Select a file based on its
939.Ar user
940name, or when starting with a
941.Cm # ,
942a numeric uid.
943A '\\' can be used to escape the
944.Cm # .
945Multiple
946.Fl U
947options may be supplied and checking stops with the first match.
948.It Fl X
949When traversing the file hierarchy specified by a pathname,
950do not descend into directories that have a different device ID.
951See the
952.Li st_dev
953field as described in
954.Xr stat 2
955for more information about device ID's.
956.It Fl Y
957This option is the same as the
958.Fl D
959option, except that the inode change time is checked using the
960pathname created after all the file name modifications have completed.
961.It Fl Z
962This option is the same as the
963.Fl u
964option, except that the modification time is checked using the
965pathname created after all the file name modifications have completed.
966.El
967.Pp
968The options that operate on the names of files or archive members
969.Fl ( c ,
970.Fl i ,
971.Fl n ,
972.Fl s ,
973.Fl u ,
974.Fl v ,
975.Fl D ,
976.Fl G ,
977.Fl T ,
978.Fl U ,
979.Fl Y ,
980and
981.Fl Z )
982interact as follows.
983.Pp
984When extracting files during a
985.Em read
986operation, archive members are
987.Sq selected ,
988based only on the user specified pattern operands as modified by the
989.Fl c ,
990.Fl n ,
991.Fl u ,
992.Fl D ,
993.Fl G ,
994.Fl T ,
995.Fl U
996options.
997Then any
998.Fl s
999and
1000.Fl i
1001options will modify in that order, the names of these selected files.
1002Then the
1003.Fl Y
1004and
1005.Fl Z
1006options will be applied based on the final pathname.
1007Finally the
1008.Fl v
1009option will write the names resulting from these modifications.
1010.Pp
1011When archiving files during a
1012.Em write
1013operation, or copying files during a
1014.Em copy
1015operation, archive members are
1016.Sq selected ,
1017based only on the user specified pathnames as modified by the
1018.Fl n ,
1019.Fl u ,
1020.Fl D ,
1021.Fl G ,
1022.Fl T ,
1023and
1024.Fl U
1025options (the
1026.Fl D
1027option only applies during a copy operation).
1028Then any
1029.Fl s
1030and
1031.Fl i
1032options will modify in that order, the names of these selected files.
1033Then during a
1034.Em copy
1035operation the
1036.Fl Y
1037and the
1038.Fl Z
1039options will be applied based on the final pathname.
1040Finally the
1041.Fl v
1042option will write the names resulting from these modifications.
1043.Pp
1044When one or both of the
1045.Fl u
1046or
1047.Fl D
1048options are specified along with the
1049.Fl n
1050option, a file is not considered selected unless it is newer
1051than the file to which it is compared.
1052.Sh EXIT STATUS
1053The
1054.Nm
1055utility will exit with one of the following values:
1056.Bl -tag -width 2n
1057.It 0
1058All files were processed successfully.
1059.It 1
1060An error occurred.
1061.El
1062.Sh EXAMPLES
1063The command:
1064.Dl "pax -w -f /dev/sa0 ."
1065copies the contents of the current directory to the device
1066.Pa /dev/sa0 .
1067.Pp
1068The command:
1069.Dl pax -v -f filename
1070gives the verbose table of contents for an archive stored in
1071.Pa filename .
1072.Pp
1073The following commands:
1074.Dl mkdir /tmp/to
1075.Dl cd /tmp/from
1076.Dl pax -rw .\ /tmp/to
1077will copy the entire
1078.Pa /tmp/from
1079directory hierarchy to
1080.Pa /tmp/to .
1081.Pp
1082The command:
1083.Dl pax -r -s ',^//*usr//*,,' -f a.pax
1084reads the archive
1085.Pa a.pax ,
1086with all files rooted in ``/usr'' into the archive extracted relative to the
1087current directory.
1088.Pp
1089The command:
1090.Dl pax -rw -i .\ dest_dir
1091can be used to interactively select the files to copy from the current
1092directory to
1093.Pa dest_dir .
1094.Pp
1095The command:
1096.Dl pax -r -pe -U root -G bin -f a.pax
1097will extract all files from the archive
1098.Pa a.pax
1099which are owned by
1100.Em root
1101with group
1102.Em bin
1103and will preserve all file permissions.
1104.Pp
1105The command:
1106.Dl pax -r -w -v -Y -Z home /backup
1107will update (and list) only those files in the destination directory
1108.Pa /backup
1109which are older (less recent inode change or file modification times) than
1110files with the same name found in the source file tree
1111.Pa home .
1112.Sh DIAGNOSTICS
1113Whenever
1114.Nm
1115cannot create a file or a link when reading an archive or cannot
1116find a file when writing an archive, or cannot preserve the user ID,
1117group ID, or file mode when the
1118.Fl p
1119option is specified, a diagnostic message is written to
1120.Dv standard error
1121and a non-zero exit status will be returned, but processing will continue.
1122In the case where pax cannot create a link to a file,
1123.Nm
1124will not create a second copy of the file.
1125.Pp
1126If the extraction of a file from an archive is prematurely terminated by
1127a signal or error,
1128.Nm
1129may have only partially extracted a file the user wanted.
1130Additionally, the file modes of extracted files and directories
1131may have incorrect file bits, and the modification and access times may be
1132wrong.
1133.Pp
1134If the creation of an archive is prematurely terminated by a signal or error,
1135.Nm
1136may have only partially created the archive which may violate the specific
1137archive format specification.
1138.Pp
1139If while doing a
1140.Em copy ,
1141.Nm
1142detects a file is about to overwrite itself, the file is not copied,
1143a diagnostic message is written to
1144.Dv standard error
1145and when
1146.Nm
1147completes it will exit with a non-zero exit status.
1148.Sh SEE ALSO
1149.Xr cpio 1 ,
1150.Xr tar 1
1151.Sh STANDARDS
1152The
1153.Nm
1154utility is a superset of the
1155.St -p1003.2
1156standard.
1157The options
1158.Fl z ,
1159.Fl B ,
1160.Fl D ,
1161.Fl E ,
1162.Fl G ,
1163.Fl H ,
1164.Fl L ,
1165.Fl P ,
1166.Fl T ,
1167.Fl U ,
1168.Fl Y ,
1169.Fl Z ,
1170the archive formats
1171.Ar bcpio ,
1172.Ar sv4cpio ,
1173.Ar sv4crc ,
1174.Ar tar ,
1175and the flawed archive handling during
1176.Ar list
1177and
1178.Ar read
1179operations are extensions to the
1180.Tn POSIX
1181standard.
1182.Sh HISTORY
1183The
1184.Nm
1185utility appeared in
1186.Bx 4.4 .
1187.Sh AUTHORS
1188.An Keith Muller
1189at the University of California, San Diego
1190.Sh BUGS
1191The
1192.Nm
1193utility does not recognize multibyte characters.
1194